It appears the project has been a success. Daan Roosegaarde (of, naturally, Roosegaarde) has announced that the bikes will be released by the end of 2017.

The bicycles purify the air using a module located between the bike's handle bars. The module catches polluted air, filters it and then releases bubbles of clean towards the cyclist's face.

The Rotterdam-based studio originally unveiled the “Smog Free Bicycles” at a TED conference in April. And if the name sounds familiar to you, yes — this is the same Roosegaarde that installed a giant "Smog Free Tower" in 798 Art District last year.

Given Ofo's 6.5 million bikes in over 150 cities and three million daily users, Roosegaarde hopes their invention can have a lasting impact on China's air.